There will be another chance to join the final leg 4:
[Tell Tours] Switzerland - "Hot Potato" (Leg 4)
I also provide an iCalendar (*.ics) file which can be imported into most calendar applications, so you can set yourself a reminder:
Tell Tours - Geneva to Samedan.ics
(Note for Firefox users: simply open the link and the *.ics file will show up as text file in the browser; then simply “Save as” that page into the corresponding *.ics file and import it into your calendar app, by opening the dowloaded file. Google Chrome / MS Edge and other browsers may simply right-click on the link and “Save target as…”)